Introduce nvim namespace: Move files.

Move files from src/ to src/nvim/.
- src/nvim/ becomes the new root dir for nvim executable sources.
- src/libnvim/ is planned to become root dir of the neovim library.

src/nvim/quickfix.h

@@ -0,0 +1,36 @@
+#ifndef NEOVIM_QUICKFIX_H
+#define NEOVIM_QUICKFIX_H
+/* quickfix.c */
+int qf_init(win_T *wp, char_u *efile, char_u *errorformat, int newlist,
+            char_u *qf_title);
+void qf_free_all(win_T *wp);
+void copy_loclist(win_T *from, win_T *to);
+void qf_jump(qf_info_T *qi, int dir, int errornr, int forceit);
+void qf_list(exarg_T *eap);
+void qf_age(exarg_T *eap);
+void qf_mark_adjust(win_T *wp, linenr_T line1, linenr_T line2,
+                    long amount,
+                    long amount_after);
+void ex_cwindow(exarg_T *eap);
+void ex_cclose(exarg_T *eap);
+void ex_copen(exarg_T *eap);
+linenr_T qf_current_entry(win_T *wp);
+int bt_quickfix(buf_T *buf);
+int bt_nofile(buf_T *buf);
+int bt_dontwrite(buf_T *buf);
+int bt_dontwrite_msg(buf_T *buf);
+int buf_hide(buf_T *buf);
+int grep_internal(cmdidx_T cmdidx);
+void ex_make(exarg_T *eap);
+void ex_cc(exarg_T *eap);
+void ex_cnext(exarg_T *eap);
+void ex_cfile(exarg_T *eap);
+void ex_vimgrep(exarg_T *eap);
+char_u *skip_vimgrep_pat(char_u *p, char_u **s, int *flags);
+int get_errorlist(win_T *wp, list_T *list);
+int set_errorlist(win_T *wp, list_T *list, int action, char_u *title);
+void ex_cbuffer(exarg_T *eap);
+void ex_cexpr(exarg_T *eap);
+void ex_helpgrep(exarg_T *eap);
+
+#endif /* NEOVIM_QUICKFIX_H */